A Pt catalyst or Pt alloy catalyst supported on an electrically conductive material is commonly used as an electrode for polymer electrolyte fuel cells (PEFC). Carbon black having a large surface area is the most widely used electrically conductive material for supporting the catalyst. However, carbon supports corrode as a result of operation over a long period of time and repeated operation/stopping cycles. When the carbon support corrodes, agglomeration or solution of the Pt occurs, and as a result the activation of the catalyst may be reduced. Also, if positive ions and negative ions contained in the moisture in the air used as an oxidizing agent or the water used to maintain the MEA in a wet state, and so on, penetrate into the fuel cell, there is a reduction in the ion exchange of the sulfonate group in the polymer electrolyte membrane and a reduction in the activation of the catalyst, and so on, so the performance of the fuel cell is reduced.
Japanese Unexamined Patent Application Publication No. 2002-198059, published on Jul. 12, 2002, reports a polymer electrolyte fuel cell that includes a polymer electrolyte membrane; an anode and cathode that sandwich the polymer electrolyte membrane; an anode-side electrically conductive separator plate having a gas flow path that supplies fuel gas to the anode; and a cathode-side electrically conductive separator plate having a gas flow path that supplies oxidizing agent gas to the cathode, wherein the anode and cathode include a gas diffusion layer and a catalyst layer, and the gas diffusion layer includes an ion catcher.
Japanese Unexamined Patent Application Publication No. 2006-185845, published on Jul. 13, 2006, reports a gas diffusion layer for a fuel cell that includes a gas diffusion base material layer and a carbon layer, wherein the gas diffusion base material layer and/or the carbon layer includes a heavy metal ion arresting agent.
Japanese Unexamined Patent Application Publication No. 2008-177132, published on Jul. 31, 2008, reports a fuel cell provided with an anion arresting layer that includes a material that produces sparingly soluble salt by reaction with anions in the flow paths through which the fuel gas or the oxidizing agent gas flows.
Japanese Unexamined Patent Application Publication No. 2009-043430, published on Feb. 26, 2009, reports a membrane electrode assembly that includes a polymer electrolyte membrane and a pair of electrodes that sandwich the polymer electrolyte membrane, wherein an intermediate layer is provided between the polymer electrolyte membrane and at least one of the electrodes, the intermediate layer includes an ion conductive material, and has acid amide bonds at the interface with the polymer electrolyte membrane and the electrode.